"rickman" wrote in message ...

On 3/26/2016 6:02 PM, Bob Wilson wrote:
On 3/26/2016 2:43 PM, Wayne wrote:
So here's the deal. I want to sit in my car in a parking lot and access
wi-fi legitimately in a nearby building.
(I'm authorized to use the system and have a password.)

The device is similar to an ipod (no phone).

I used a passive RF sniffer around the case and found a sweet spot that
has significant RF output.

What I want to experiment with is a coupling loop over the case sweet
spot going to a coax and then a directional antenna.

It would be acceptable to simply scotch tape the loop on the case.

Any suggestions on the antenna would be appreciated.

Wayne
W5GIE


You may have thought about this... You might need to amplify your
receive signal, the device (whatever it is) needs to talk both ways.
Bob W

Whatever you do with the antenna should work in both directions, no?

That's the plan. A bidirectional passive system with maximum coupling of
the ipod to transmission line.

Today I tried a loop pickup at the ipod to some RG-58 that has a pickup loop
at the other end.
I'm getting nearly the same level with the RF sniffer at the ipod or at the
remote end of the cable.
One difficulty is that the ipod doesn't transmit all the time, and that
affects attempts to optimize the coupling.

If I can optimize the pickup loop, I could permanently attach it inside a
slip on cover I have for the ipod.

I'm drawing a blank on a good/easy to build antenna.

Wayne wrote:
I'm drawing a blank on a good/easy to build antenna.

It of course depends on the frequency you are going to use.
WiFi antennas with gain (both directional and omni) are available
off-the-chinese-shelf (i.e. at prices you are not going to beat), but
of course you can always use one of the wellknown technologies to
make one yourself. i.e. a yagi, loop, doublequad, dish, etc.

But first find out on what frequency you are!